Preterm birth, which is defined as a baby born before 37 weeks of pregnancy, is incredibly common in the U.S, affecting 1 out of every 10 infants.¹

When a baby is born too early, organs including the brain, lungs and liver do not have a chance to fully develop and as a result there is an increased risk of long-term neurological and other disabilities and death.

Preterm birth is the greatest factor leading to infant death, especially among those born very preterm (before 32 weeks). Babies born too early may also experience:²

• Breathing problems
• Feeding difficulties
• Cerebral palsy
• Developmental delay
• Vision and hearing problems

The cause of preterm birth is often said to be unknown, and associated risk factors you may hear from your conventional physician include high blood pressure during pregnancy, infection, extreme stress, carrying more than one baby, prior preterm birth, and use of tobacco, alcohol or controlled substances.

However, there are other factors that may play a primary role in preterm birth that are rarely talked about and certainly do not typically get brought up during a typical prenatal care appointment — but they should.

If you’re a parent-to-be or planning to start a family, here are tips to help support a healthy, full-term pregnancy.

Optimize Your Vitamin D Levels

The moment you find out you’re pregnant, and ideally well before, have your vitamin D levels tested and take steps to increase them if necessary—to at least 40 ng/mL.

In a study published in The Journal of Steroid Biochemistry and Molecular Biology, women with serum 25(OH)D (vitamin D) concentrations of 40 ng/mL or higher had a 57 percent lower risk of preterm birth compared to those with concentrations of 20 ng/mL or less.³

Among Hispanic women, the rate of decrease was even more striking — 79 percent — for those with vitamin D levels of at least 40 ng/mL, while black women had a 45 percent lower risk of preterm birth when their vitamin D levels were at least 40 ng/mL. The authors concluded:⁴

“The March of Dimes estimates that the annual cost of preterm births in the United States is $12 billion (for 455,918 children).

If approximately 50 percent of preterm births could be prevented in the general population, as this analysis suggests is possible, there could be $6 billion available for other services and more than 225,000 children and families spared this trauma.

In light of this, practice guidelines at the Medical University of South Carolina (MUSC) and other institutions are currently being changed to prospectively target 40 ng/mL for pregnant women with the goal of dramatically lowering preterm birth rates.”

Separate research has also revealed that the risk of preterm birth significantly decreased as levels of vitamin D increased up to about 40 ng/mL and then plateaued.⁵

Yet another study found women with the lowest levels of vitamin D were 1.5 times more likely to deliver early than those with the highest levels, perhaps because vitamin D helps reduce bacterial infection in the placenta, which may trigger early delivery.⁶

Vitamin D Screening and Monitoring Are Key

Vitamin D screening is key, as this is the only way to determine whether you might be deficient or not, and regular testing is important to make sure whatever dosage of vitamin D you're taking is sufficient to reach clinically relevant levels.

GrassrootsHealth, which is compiling vitamin D data from a number of population-based studies, recommends maintaining a vitamin D blood serum level of 40 to 60 ng/mL to protect your and your baby's health.

However, according to previous studies, your levels need to be above 50 ng/mL to protect your baby from serious complications, such as preterm delivery and preeclampsia.⁷ So please, if you’re pregnant, make sure to get your 25 hydroxy D levels checked.

While optimizing your vitamin D through sensible sun exposure is best, if this isn’t possible Dr. Bruce Hollis’ research indicates that 50 percent of women can achieve this level with 4,000 IUs daily during pregnancy and 6,400 IUs (for nursing mothers) of vitamin D3 on a daily basis.

But again, you’ll need to have your vitamin D levels tested and monitored to be sure you’re within the optimal range.